Emery ribbon feed and rewinder for sander



Nov.- 17,1970 (5. R. MAHONEY EMERY RIBBON FEED AND REWINDER FOR SANISERFiled June 28, 1965 2 Sheets.. heet l I N VE NTOR: 620265 A. M4,

BY Mad W h ls Ar 2,5;

United States Patent 3,540,169 EMERY RIBBON FEED AND REWINDER 1 9RSANDER George R. Mahoney, 5749 Arapaho Drive, San Jose, Calif. 95123Filed time 28, 1965, Ser. No. 467,295 Int. Cl. 324d 13/06 11.5. C1.51-335 11 Claims ABSTRACT OF THE DISCLOSURE A rotary sander in which aplurality of emery strips extend radially from the slit peripheral wallof a drum housing and backed by brush bristles on such periphery. Amount for pairs of such emery strips looped about pins circumferentiallyarranged on a disc within the drum housing and extending into bores in acover for driving relation therewith and relative thereto at the optionof the user.

This invention relates to improvements in a rotary abrasive device ofthe type having a drum for sanding irregular as well as flat surfaces ofarticles of metal, wood or the like.

Drum type sanders as is generally known consist of a hollow drumprovided with radially extending brushes adjacent which sanding ribbonsextend from a mounting within the drum. The general arrangement is suchthat the sanding ribbons are replaceable and mountable for extension andretraction relative to the drum.

The present invention is directed to a novel arrangement of emeryribbons, a mount therefor cooperating with the cover of the drum forreleasing and/ or rewinding emery ribbons, and means for interlockingthe cover relative to the drum.

It is an object of this invention to provide a simple yet effective andeconomical way of supplying and preparing the emery strips for mountingin a sanding drum.

It is another object to provide a novel and simple mounting for theemery strips and for relating the latter with the cover for the drum insuch a manner as to facilitate rewinding of the strips within the drumor feeding of the strips outwardly from the drum.

It is a further object to provide the cover and drum with interlockingmeans segmentally spaced to assure locking of the same and ribbon stripsin desired positions of extension relative to the drum.

These and other objects and advantages of the present invention willbecome apparent from a reading of the following description and claimsin the light of the two sheets of drawing in which:

FIG. 1 is a plan view of a rotary sander with cover removed toillustrate a portion of the present invention embodied therein.

FIG. 2 is a section through the entire rotary sander of FIG. 1 and takensubstantially along line 22 thereof.

FIG. 3 is an exploded perspective view of the parts of the presentinvention illustrating their interrelationship with each other.

Referring to FIG. 2 the sanding drum 10 has a central shaft 11 press fitand keyed thereto for turning the same. The drum 10 is cup shaped havinga solid side wall 12 formed integrally with a peripheral wall 13 whichis cylindrical and of a desired depth. The drum 10 is die cast directlyonto the shaft 11 so as to become a part thereof and one end of theshaft 11 extends beyond the side wall 12 to fit into the chuck of apower tool (not shown) for rotation thereby. The shaft 11 extendsthrough the drum 10 and has its opposite end 14 threaded to receive anut N which is knurled. A cover C for the drum 10 is also die cast andhas a center bore B sized to fit the shaft 11.

The peripheral wall 13 of the drum 10 has a plurality of segmental lands15 divided by a plurality of circumferentially space slits or openings16 each of sufiicient clearance to allow a fiat ribbon strip of emerycloth 17 to pass through. The slits 16 run the full width of theinterior of the drum 10 and extend from the inner face of the side wall12 thereof and open up onto the opposite open side of the drum. In thepresent disclosure six lands 15 and six slits 16 are shown. Each land 15has a brush mounting groove 18 formed therein to receive the mountingblock 19 of a brush 20, the bristles of which extend radially outwardfrom the drum adjacent the trailing side of an adjacent slit 16.

The brushes 20 serve as a resilient backing for each strand of emerycloth 17 the back face 21 of which engages the brush to present theabrasive surface 22 of the emery cloth 17 to the article to be sanded.The brushes 20 and strips of emery cloth 17 are substantially the widthof the interior 23 of the drum and inner ends of the strips 17 aremounted therein in a manner now to be explained.

A mount for the emery cloth strips 17 designated 25 comprises a flatdisc 26 provided with a central bore 27 which fits over the shaft 11which extends transversely and axially through the drum 10. The innerface of the side wall 12 of the drum has a recess 28 formed therein toreceive the disc 26, the disc and recess 28 having substantially thesame thickness and depth so that the inner surface of the disc liesflush with the inner surface of the side wall of the drum.

The disc 26 is free to turn about the shaft 11 and is firmly centeredrelative thereto and relative to the base of the recess 28. A pluralityof pins 29 are mounted on the inner face of the disc 26 and extendupwardly there from across the interior 23 of the drum and slightlybeyond the open side thereof. There is one such pin 29 for each pair ofslits 16 through which the emery cloth strips 17 extend. There being sixstrips 17 there are three pins 29 equally spaced in tripod fashion uponthe disc 26.

In accordance with the present invention the strips 17 of emery clothare joined in pairs with their abrasive surfaces 22 facing in one andthe same direction. In other words, one strip 17 is laid with itsabrasive surface 22 down and another strip 17 is laid over it with theabrasive surface 22 thereof against the back surface 22 of the lowermoststrip 17. The two strips 17 thus disposed are then secured together by awire staple 30 adjacent one end 31 of the two strips. This is done withany well known form of stapling machine or device. The two strips 17thus joined are mounted on one of the pins 29 and the balance of eachstrip is strung out through separate and adjacent slits 16 in theperipheral wall 13 of the drum.

Now when the mount 25 for the strips 17 is turned within and relative tothe drum 10 all of the strips 17 will be wound about the equally spacedpins 29 and become neatly stored and coiled about the same within theinterior of the drum.

To facilitate turning of the mount 25 within the drum 10 the cover C isemployed. For this purpose each of the pins 29 on the mount 25 extendinto and are received by a corresponding round recess 32 provided in thecover C. The recesses 32 are tapered from a large opening at the innersurface 33 of the cover and are centered to register with the three pins29 on the mount 25. The cover C is adapted to be turned by hand whilethe drum 10 .is held stationary. In this manner, the turning movement ofthe cover C is transmitted to the pins 29 and the latter turned with thedisc 26 about the shaft 11 to wind the several pairs of emery strips 17about the mount 25.

The several strips of emory cloth are stored within the drum and eachstrip 17 has its outer end '35 disposed at approximate alignment withthe end 36 of the adjacent bmsh 20.

The cover is secured tightly upon the drum by means of the knurled nut Nwhich is turned down upon the threaded end 14 of the shaft 11 to holdthe cover with its inner surface 33 against the surface 38 at the openside of the drum. By turning the nut N slightly, back upon its threadedconnection with the shaft 11 the several strips 17 can be pulled tounwind them relative to the mount 25 and to extend them beyond the outerends 36 of the brushes. Any worn emery surface 22 of the strips can thenbe clipped (severed) off to present fresh abrasive surfaces 22 to thearticle to be sanded.

In order to prevent the strips 17 from being pulled out accidentally,that is, unintentionally, or other than when desired, a locking or limitmeans 40 is provided between the cover and drum. The locking or limitmeans 40 comprises a plurality of projections or knobs 41 formed on thesurface 38 at the open side of the drum and a plurality of recesses 42formed in the inner surface 33 of the cover C. As best seen in FIG. 3there is one such knob 41 on each of the six lands or segmental portionsof the drum. In the present disclosure I have shown double that numberor twelve recesses 42 formed on the inner face 33 of the cover. Theserecesses 42 are the same radial distance from center as the knobs butextend arcuately in the cover so that any particular set of alternaterecesses will register with the knobs 41 on the drum. Consequently, ifthere is any slippage of the mount by reason of undue pull on the freeends of the several strips of emery cloth ,17 the knobs 41 willultimately engage the far end of the recesses in which they are disposedand thereby limit and stop further turning of the cover relative to thedrum. In this manner the cover will be locked against :further turningand mount 25 will be statically held against turning within the drum.

For purposes of safety, the cover has a peripheral lip 45 depending fromits inner face 33 and the wall 13 of the drum has a correspondingannular shelf 46 of reduced diameter to meet and receive the lip 45. Thesharp edges at the open upper ends of the slits 16 and the brush mounts18 are thus covered and guarded against snagging the article beingsanded.

From the foregoing it will be appreciated that there is provided a verysimple, inexpensive, and efficient manner of supplying emery strips fora rotary sander. The strips can be cut from a larger sheet and securedtogether in the manner described for mounting as pairs on the severalpins 29 of the mount 25. The mount 25 is itself simple yet effective andsubstantial to provide a storage or supply of emery strips and forsecuring the latter relative to the sanding drum.

The present invention further provide a novel limiting and locking meansbetween the cover and drum whereby to assure anchorage of the severalstrips of emery cloth within the drum and against accidental slippagebetween the mount and the drum.

While I have described my new improvements in the emery ribbons, mount,feed and rewinder for a drum type sander in specific detail, it will beappreciated that the same is susceptible to modifications, alteration,and/ or variations without departing from the spirit of the inventiontherein. I therefore desire to avail myself of all modifications,alterations and/ or variations as may come within the purview of theappended claims.

What I claim as new and desire to protect by Letters Patent is:

1. The combination with a sander drum having a side wall from whichextends a centrally located shaft and a cylindrical peripheral wallhaving a plurality of circumferentially spaced lands divided by spacedlongitudinal slits and a brush extending radially from each landadjacent a respective slit, a plurality of strips of emery cloth 4 andmeans for mounting the same within said drum com prising:

(a) means for securing said strips of emery cloth in pairs adjacent oneend thereof with the abrasive side of each facing in the same directionand each for 5 extension through a respective one of said slits forbacking against an adjacent brush, (b) a mount in said drum comprising adisc mounted on such shaft for rotation thereabout, 10 (c) a pluralityof pins extending from said disc and each straddled by a pair of saidstrips where the latter are secured together,

(d) and a cover for said drum mounted on such shaft and having aplurality of recesses registerable with said pins for receiving andengaging the same for turning said pins and disc aobut said shaft forwinding said ribbon strips about said mount.

2. The combination with a sander drum having one side closed by a wallfrom which extends a centrally lo- 20 cated shaft and a concentriccylindrical peripheral will having a plurality of circumferentiallyspaced lands divided by spaced longitudinal slits and a brush extendingradially from each land adjacent a respective slit, a plurality ofstrips of emery cloth and means for mounting the 25 same within saiddrum comprising:

(a) means for securing pairs of said strips of emery cloth togetheradjacent one end thereof with the abrasive side of each strip facing inthe same direction,

(b) a mount for said strips comprising a disc arranged on such shaft forrotation thereabout within such drum.

(c) a pin extending from said disc between each pair of said strips andengaging said strips where the pairs of strips are secured together,each of said strips having their free ends extending through arespective one of said slits in the peripheral side wall of said drumand backing against an adjacent brush,

3. The combination with a sander drum having an open sided cylindricalperipheral wall having a plurality of circumferentially spaced landsdivided by spaced longitudinal slits and each secured to a side wallhaving a shaft extending therethrough concentric to said peripheralwall, and a brush extending radially from each land adjacent arespective slit to provide a backing for a plurality of strips of emerycloth each extending through a respective one of said slits from withinsaid drum of means for mounting said strips of emery cloth within saiddrum comprising:

(a) separate means for securing each pair of said strips of emery clothtogether adjacent one end thereof with the abrasive side of each stripfacing in a direction to expose its abrasive side opposite to that sidethereof bearing against an adjacent brush,

(b) a disc mounted for rotation on such shaft within said drum,

(c) a pin extending from said disc between each pair of said strips forengaging that end of the latter where they are secured together,

(d) a solid cover for said drum mounted on such shaft for closing theopen side thereof, said cover having a plurality of recessesregisterable with the pins on said disc for receiving and engaging saidpins and for turning said pins and disc about said shaft and relative tosaid drum for winding said strips of emery cloth into said drum,

(e) and a nut threaded on said shaft for securing said cover to saiddrum.

4. The device of claim 3 including means for limiting relative turningof said cover relative to said drum comprising a projection on the openface of said peripheral wall, and a recess formed on the innerside ofsaid cover engageable by the projection on the open face of saidperipheral wall.

5. The device according to claim 3 in which each land has a projectionthereon, and means on the inner face of said cover for receiving andengaging one or another of said projections for limiting turning of saidcover relative to said drum.

6. In a rotary sander of the type having an open sided cylindricalperipheral wall consisting of a plurality of circumferentially spacedlands divided by spaced longitudinal slits and secured to a solid sidewall having a drive shaft secured thereto and extending therethrough,and a brush extending radially from each land adjacent a respective slitproviding a backing for a plurality of strips of emery cloth eachextending through a respective one of said slits; the combinationtherewith of means for mounting said strips within said drum comprising:

(a) a staple securing each pair of said strips of emery cloth adjacentone end thereof with the abrasive side of each said strip facing in acommon direction for backing against an adjacent brush,

(b) a recess formed on the inner face of the solid side wall of saiddrum concentric to said shaft and peripheral Wall,

(c) a disc mounted on such shaft for rotation thereabout and seated inthe recess formed on the inner face of said solid side wall to disposethe inner face of said disc in flush relation with the inner face ofsaid solid side wall,

(d) a plurality of pins extending from the inner face of said disc, onesuch pin extending between each pair of said strips where the latter aresecured together,

(e) a cover for the open side of the peripheral wall of said drum andmounted on such shaft, said cover having a plurality of recesses formedtherein for receiving and engaging the free ends of said pins forturning said pins and said disc about said shaft for winding said ribbonstrips about said mount,

(f) and a nut threaded onto said shaft exteriorly of said cover forsecuring the latter to the open side of the peripheral wall of saiddrum.

7. The device of claim 6 including means for limiting relative turningof said cover relative to said drum comprising a projection on the openface of said peripheral wall, and a recess formed on the innerside ofsaid cover engageable by the projection on the open face of saidperipheral wall.

8. The device according to claim 6 in which each land has a projectionthereon, and means on the inner face of said cover for receiving andengaging one or another of said projections for limiting turning of saidcover relative to said drum.

9. The combination with a rotary sander of the type having an open sidedcylindrical peripheral wall consisting of a plurality ofcircumferentially spaced lands divided by spaced longitudinal slits andeach secured to a solid side wall having a drive shaft securedconcentric thereto and extending beyond the open side of said peripheralwall, the said lands each having a brush extending radially outwardtherefrom adjacent a respective slit and providing a backing for aplurality of strips of emery cloth secured in pairs by having theirinner ends joined; an emery strip mount and rewinding means comprising:

(a) a disc mounted on such shaft for rotation thereabout and bearingagainst the inner face of said solid side wall,

(b) a plurality of pins extending from said disc beyond the open side ofsaid peripheral wall for receiving a pair of said strips where thelatter are secured together,

(c) a solid cover for the open side of said peripheral wall having acentral bore to receive the extended end of said shaft and having aplurality of recesses registerable with said pins for receiving andengaging the extended ends thereof for turning said pins and disc aboutsaid shaft for Winding said strips about said pins,

(d) and means on the extended end of said shaft exteriorly of said coverfor securing the latter onto the open side of said peripheral wall.

10. The device of claim 9 including means for limiting relative turningof said cover relative to said drum comprising a projection on the openface of said peripheral wall, and a recess formed on the innerside ofsaid cover engageable by the projection on the open face of saidperipheral wall.

11. The device according to claim 9 in which each land has a projectionthereon, and means on the inner face of said cover for receiving andengaging one or another of said projections for limiting turning of saidcover rela tive to said drum.

References Cited UNITED STATES PATENTS 2,533,619 12/1950 Pokras 51-3352,600,613 6/1952 Bruner 51-335 2,601,499 6/ 1952 Bruner 51-335 2,709,3235/1955 Swan 51335 2,771,721 11/1956 Reimar 51335 3,132,452 5/1964 Block51335 LESTER M. SWINGLE, Primary Examiner D. G. KELLY, AssistantExaminer

